Abstract:
To address the increasing prevalence of dysphagia associated with global population aging and to enhance the safety and palatability of food for affected individuals, this study aims to develop 3D-printable composite hydrogels based on pea protein (PP) in combination with various polysaccharides for the creation of easy-to-swallow foods.
κ-Carrageenan (Car), corn starch (CS), and sodium alginate (SA) were respectively combined with PP to prepare three types of composite inks (PP-Car, PP-CS, and PP-SA). The rheological properties, textural characteristics, printability, and swallowing suitability of the hydrogels were systematically investigated. Results showed that all three composite inks exhibited shear-thinning behavior and good thixotropic recovery, making them suitable for extrusion-based 3D printing. With increasing concentrations of polysaccharides, the viscosity and storage modulus (G') of the printing inks significantly increased, along with the hardness of the resulting hydrogels. Specifically, the hardness values of PP-1.5% Car-G, PP-15.0% CS-G, and PP-1.5% SA-G were 626.49 g, 790.67 g, and 287.85 g, respectively, indicating enhanced gel structure. 3D printing tests demonstrated that the PP-Car and PP-CS inks produced constructs with well-defined structures and clear textures, showing superior structural integrity compared to the PP-SA system. In terms of swallowing properties, all hydrogels met the criteria of Level 7 as defined by the International Dysphagia Diet Standardisation Initiative (IDDSI), corresponding to regular, easy-to-chew textures. This study successfully developed three plant protein-based composite hydrogel systems with good 3D printability and swallowing performance, providing a reference for the personalized development of easy-to-swallow foods using 3D printing technology.